Xray-tube.



T. B. RIDER.

X-RAY TUBE.

APPLICATION FILED .mn l0, $941..

Patented Dec. 10, 1-918.

THOMAS B. RIDER, or Los ANGELES, CALIFORNIA, ASSIGNOR, BY MESNE ASSIGNMENTS,

OF ONE-HALF T0 GEOBGIET A DE CASTRO-DANZIGER, mil: MCCLELLAN, OF LOS ANGELES,

CALIFORNIA.

X-RAY TUBE.

Specification of Letters Patent. Patented Dec. 10, 1 91 8. I

. Application filed May 10, 1917, Serial No. 167,712.

My invention relates to improvements in X-ray tubes; and the objects of my improvements are, to regulatethe focus between the cathode and the anode in an X-ray tube; to

- provide a cathode which will bring the focus slightly ofi the center on the anode; to provide an X-ray tube which allows a regulation of the focal distance while the X-ray tube is in use; toprovide a cathode which allows the regulation of the focus so as to meet the anode in different points after the first met point has been ruined in the surface of the anode; the invention consisting in the construction, combination'and arrangement of devices hereinafter more fully described and claimed, and illustrated in the accompanying drawing, in which The figure is an assembly of an X-ray tube with my device inserted.

Similar numbers refer to similar parts throughout the papers.

1 designates the glass globe of the X-ray tube, 2 designates an extension glass tube closed at the end 3 surrounding a steel tube 4. A wire 5 is fused into and through the closed end 3 outwardly forming one of the,

connections 6 forthe electric circuit and inwardly connecting to the steel tube 4. An anode 7 is secured to the free end of the steel tube having preferably a tungsten disk 8 inserted into the surface. Another glass extension tube 9 serves as a holder for theauxiliary anode 10, which is*connected to the connection of the main anode by the wire 11. A third extension'cnd 12 is pro vided for thephemical vacuum regulator, a

' stem is the concave-faced cathode member 19. As will be seen in the drawing, the threaded bore 20 is eccentrically positioned in relation to the concaved face 21 of the cathode member 19, and, having the cathode made of material which can be influenced by a magnet, or having a piece 22 of suitable material secured to the side of the cathode, it will easily be understood that the cathode can be operated from the outside by holding' a magnet to the glass extension tube 16 near the cathode and then turn the whole X-ray tube, or move the magnet around the glass extension tube 16 in the direction in which the cathode is wanted to turn, and, in thus turning the cathode'on the eccentrically disposed bore, it will be understood that the focus can be directed toward difl'erent points on the surface of the anode.

Having the cathode threaded on the stem 17 serves also to lengthen or shorten the focal distancebetween the cathode 19 and the anode 7, as will also be easily understood.

It will furthermore be understood that the cathode member 19 can be turned on the threaded end 18 of the stem 17 by shaking the X-ray tube, as the overweight formed by the eccentric position of the cathode member and the extra weight 22 formed on the cathode will cause the cathode to turn,"theweighted side of the cathode keeping on the undersidewhile'the X-ray tube is shaken and simultaneously turned.

I am aware that X-ray'tubes of various constructions are known, but to lengthen the life of X-ray tubes and improve the devices by the several means described above, I claim 1. In an X-ray tube a cathode having turnable supporting means eccentrically disposed in relation to the focusing face.

2. In an X-ray tube a cathode having its, supporting means eccentrically disposed in relation to the focusing face, and having a weight-body provided on one side of the cathode of suitable material to be influenced by a magne't from the outside of the X-ray tube.

3. In an X-ray tube" an anode projecting into the X-ray tube from one side, a cathode stem projecting into the X-ray tube from the opposite side and threaded on its free end, and a cathode member eccentrically turnably 'mounted on the threaded end of the stem for focusing the cathode toward different points inthe surface of the anode.

' 4. In an X-ray tube an anode projecting into the X-ray tube from one side, a cathode stem projecting into the X-ray tube from the opposite side, and a cathode member turnably mounted on the end of the stem having a wncaved face transverse to the stem, the center of the conceived face being eccentrically disposed to the center of the supporting stem.

5. In an X-ray tube an anode projecting into the X'ray tube from one side, a cathode stem projecting into the X-ruy tube from the opposite side and threaded on its free I end, a cathode member turnably mounted on the threaded end of the stem having a conceved face toward the anode transverse to the stem, the center of the concaved face being eccentrically disposed in relation to the center of the supportingstem, and means formed on the cathode member for turning the cathode'in-the X-ray tube when so desired.

In testimony n 'hereofl hereunto aflix my signature in the presence of two Witnesses.

THOMAS B. RIDER.

@epter of thin patent may be obtained for five cent: each, by addressing the "iiommfiaeienex' e! Estonia, Washington, E. e, 

